Spark plugs

[philj]

Been reading spark plug threads, and the recommended Bosch F5DPOR breaks.

So why is another Bosch recommended? The FR5DP ?

Then I've found 2 NGK recommendations, the PFR7B and the NGK BKR-7EIX? The P's are platinum, and IX are Iridium, the latter being a touch cheaper. What is the difference between those 2 NGKs? At what point should you go for 8s?

My cars just chipped with an exhaust on stock coils. Which would be better for it?

How does having the upgraded coils change what spark plugs you need?

Cheers

[Error404]

A lot of people are running the BKR-7EIX very successfully. Not sure the break point to move to the 8s but certainly not necessary with the stock turbo.

[andy10v]

Stock Replacement good for upto 450-500hp BKR-7EIX good for all year round use.

http://www.s2forum.com/forum/showthread.php?p=794152#post794152

[Thuppu]

BKR7EIX works like charm at 600hp and E85.

[Greg_S]

When I change mine I'll try the BKR7EIX or the 8's. I have a set of PFR7B's that have only done a few hundred miles as mine didnt like running on those. May just need regapping thought

[philj]

Cheers, but aren't most of you running the upgraded coils? I was reading a thread on another forum found via google (which I can't find at the moment) which seemed to imply spark plug choice depended on which coils you were running?

[M_GORDON]

Hi!
I don't remember whos, but I bought some NGKs too and the car don't runs OK.
Now they are on a box... and already runing with some old F5DPORs.

I think, they are too colds for my zone. I prove them on winter.

[Greg_S]

I'm running standard ABY coils, I don't remember seeing anything about needing different could though. Only that it's cheaper to fit later could than originals if they fail

[Cottis]

I run an old standard 3B engine (apart from Turbo, Exhausts and chip) and recently upgraded to NGK Iridiums 7EIX. They seem faultless to me.

[treebirch]

I am have just changed from the standard Bosch plug to NGK PFR7B on my RS2 which is chipped, has an exhaust and K&N panel filter and it's running very nicely.

[philj]

Thanks for the replies.

Aside from platinum vs iridium, does anyone know the differences between the PFR7B and 7EIX?

[EspenW]

I run the Bosch F3CS. Stock coils, so had to gap them to 0.45mm (they are 0.6mm out of the box) since I'm running on E85 that puts more strain on the igition system due to much richer AFR (stoich is approx. 9.6:1.

Note: if running these, do not regap a used plug, we have seen multiple instances of the ground electrode breaking off when that is done.
They are cheap, so if they need a regap, buy new ones.

[Greg_S]

What are the F3CS like for use with normal super unleaded?

[EspenW]

What are the F3CS like for use with normal super unleaded?

Likely on the cold side for street use, so they might foul.
This is not an issue on E85, since it burns much cleaner.
Reason why we use a colder plug on E85 is that while E85 is amazingly resistant to detonation (often more so than racefuel), it does not have quite the same resistance to preignition as racefuel. The colder plug lowers the risk of preignition, and since E85 burns clean, we won't see problems with fouling.